This invention relates to a laser irradiating apparatus for thermotherapy.
Recently, laser beam application to a medical field has been exploited remarkably. Similarly, (local) thermotherapy has been put into the limelight as an effective therapy for cancer recently. According to this therapy, laser beam is irradiated for 10 to 25 minutes to keep a cancer tissue at a temperature of 42.degree. to 44.degree. C. for letting the tissue die. The effectiveness of this therapy has been reported, by N. Daikuzono (inventor of the present invention) et al in the journal of Nihon Laser Igaku-kai, Vol. 6, No. 3 (Jan. 1986), pp. 71 to 76 and pp. 347 to 350.
In this case, a single probe is used for emitting laser beam generated by a laser beam generator and it is inserted in a tissue to be treated, while the laser beam is irradiated from the probe. At the same time, to keep the tissue temperature at a temperature of 42.degree. to 44.degree. C., a tip end of a temperature sensor paired with the probe is also inserted in the tissue to measure the tissue temperature and control the on-off operation of a shutter provided in a laser beam guide system which connects the laser beam generator and the probe.
On the other hand, Dougherty et al reported in 1978 about this therapy that when hematoporphyrin derivatives (HpD) were injected intervenously and weak beam of argon laser or argon pigment laser was irradiated after 48 hours, said HpD generated a first-order oxygen to show a strong carcinostatic activity. This therapy has then been watched and many researches have been reported, including a report in the journal of Nihon Laser Igaku-kai, Vol. 6, No. 3, pp. 113 to 116. It has also been known that pheophobide a is employable as a photoreactive agent. As a laser beam, there has been used YAG laser.